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                    3.2019-12-31-git教程
            
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                    1.2019-12-30-beego基本使用
            
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                    [java]
            
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                    1.2019-12-30-环境变量和系统属性
            
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                    2.2019-12-31-cloud-native-云原生
            
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                    3.2019-12-31-java语法难点
            
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                    9.2020-01-12-缓存穿透-缓存击穿-缓存雪崩概念及解决方案
            
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                    10.2020-01-13-事务笔记
            
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                    11.2020-01-13-幂等性
            
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                    12.2020-01-16-java基本语法
            
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                    [arthas]
            
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                    1.2019-12-28-arthas-example
            
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                    2.2019-12-28-arthas添加支持执行历史命令的shell功能
            
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                    3.2020-01-10-思考性能调优
            
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                    4.2020-01-10-性能调优举例-最佳实践
            
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                    5.2020-01-10-性能调优举例一
            
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                    6.2020-01-10-性能调优举例三
            
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                    7.2020-01-10-性能调优举例二
            
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                    8.2020-01-10-性能调优举例四
            
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                    9.2020-01-15-性能调优举例五
            
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                    10.2020-05-12-性能调优举例六
            
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                    11.arthas-mind-map
            
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                    [dubbo]
            
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                    1.2019-12-28-dubbo涉及的技术
            
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                    2.2019-12-30-dubbo消费者访问流程
            
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                    3.2019-12-30-dubbo面试
            
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                    [jdk]
            
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                    1.2020-01-12-实例介绍 JAVA 泛型基础
            
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                    2.2020-01-13-ThreadLocal六连问
            
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                    [jvm]
            
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                    1.2019-12-30-性能调优
            
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                    [netty]
            
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                    1.2020-01-16-netty入门
            
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                    2.2020-01-16-netty核心概念
            
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                    [solr]
            
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                    1.2019-12-28-solr-7.6.0.tgz安装
            
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                    [spring]
            
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        <li class="chapter " data-level="2.13.1" data-path="../spring/2020-01-12-SpringBoot属性读取方式介绍.html">
            
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                    1.2020-01-12-SpringBoot属性读取方式介绍
            
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        <li class="chapter " data-level="2.13.2" data-path="../spring/2020-01-12-使用spring boot+mybatis plus快速入门.html">
            
                <a href="../spring/2020-01-12-使用spring boot+mybatis plus快速入门.html">
            
                    
                    2.2020-01-12-使用spring boot+mybatis plus快速入门
            
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        <li class="chapter " data-level="2.13.3" data-path="../spring/2020-01-13-spring-initMethod-destoryMethod.html">
            
                <a href="../spring/2020-01-13-spring-initMethod-destoryMethod.html">
            
                    
                    3.2020-01-13-spring-initMethod-destoryMethod
            
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        <li class="chapter " data-level="2.13.4" data-path="../spring/2020-01-13-spring循环依赖.html">
            
                <a href="../spring/2020-01-13-spring循环依赖.html">
            
                    
                    4.2020-01-13-spring循环依赖
            
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        <li class="chapter " data-level="2.13.5" data-path="../spring/2020-01-13-spring源码随记.html">
            
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                    5.2020-01-13-spring源码随记
            
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        <li class="chapter " data-level="2.13.6" data-path="../spring/2020-01-13-自定义mini-spring.html">
            
                <a href="../spring/2020-01-13-自定义mini-spring.html">
            
                    
                    6.2020-01-13-自定义mini-spring
            
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        <li class="chapter " data-level="2.14" >
            
                <span>
            
                    
                    [websocket]
            
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        <li class="chapter " data-level="2.14.1" data-path="../websocket/2019-12-30-webscoket-springboot通信.html">
            
                <a href="../websocket/2019-12-30-webscoket-springboot通信.html">
            
                    
                    1.2019-12-30-webscoket-springboot通信
            
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        <li class="chapter " data-level="2.15" >
            
                <span>
            
                    
                    [linux]
            
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        <li class="chapter " data-level="2.15.1" data-path="../../linux/2019-12-28-Linux常用命令和快捷键.html">
            
                <a href="../../linux/2019-12-28-Linux常用命令和快捷键.html">
            
                    
                    1.2019-12-28-Linux常用命令和快捷键
            
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        <li class="chapter " data-level="2.15.2" data-path="../../linux/2019-12-28-从零到一环境安装.html">
            
                <a href="../../linux/2019-12-28-从零到一环境安装.html">
            
                    
                    2.2019-12-28-从零到一环境安装
            
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        <li class="chapter " data-level="2.15.3" data-path="../../linux/2019-12-30-vi-常用命令.html">
            
                <a href="../../linux/2019-12-30-vi-常用命令.html">
            
                    
                    3.2019-12-30-vi-常用命令
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="2.15.4" data-path="../../linux/2019-12-31-awk命令.html">
            
                <a href="../../linux/2019-12-31-awk命令.html">
            
                    
                    4.2019-12-31-awk命令
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="2.15.5" data-path="../../linux/2019-12-31-cup信息分析.html">
            
                <a href="../../linux/2019-12-31-cup信息分析.html">
            
                    
                    5.2019-12-31-cup信息分析
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="2.15.6" data-path="../../linux/2019-12-31-shell编程.html">
            
                <a href="../../linux/2019-12-31-shell编程.html">
            
                    
                    6.2019-12-31-shell编程
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="2.15.7" data-path="../../linux/2019-12-31-top命令.html">
            
                <a href="../../linux/2019-12-31-top命令.html">
            
                    
                    7.2019-12-31-top命令
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="2.15.8" data-path="../../linux/2019-12-31-普通用户docker的问题.html">
            
                <a href="../../linux/2019-12-31-普通用户docker的问题.html">
            
                    
                    8.2019-12-31-普通用户docker的问题
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="2.15.9" data-path="../../linux/2020-01-01-centos7 安装kubernetes.html">
            
                <a href="../../linux/2020-01-01-centos7 安装kubernetes.html">
            
                    
                    9.2020-01-01-centos7 安装kubernetes
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="2.15.10" data-path="../../linux/2020-01-01-centos安装常用配置.html">
            
                <a href="../../linux/2020-01-01-centos安装常用配置.html">
            
                    
                    10.2020-01-01-centos安装常用配置
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="2.15.11" data-path="../../linux/2020-01-01-docker使用.html">
            
                <a href="../../linux/2020-01-01-docker使用.html">
            
                    
                    11.2020-01-01-docker使用
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="2.15.12" data-path="../../linux/2020-01-01-kubernetes使用.html">
            
                <a href="../../linux/2020-01-01-kubernetes使用.html">
            
                    
                    12.2020-01-01-kubernetes使用
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="2.15.13" data-path="../../linux/2020-05-12-PG有用的SQL.html">
            
                <a href="../../linux/2020-05-12-PG有用的SQL.html">
            
                    
                    13.2020-05-12-PG有用的SQL
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="2.15.14" data-path="../../linux/2020-05-12-vim命令.html">
            
                <a href="../../linux/2020-05-12-vim命令.html">
            
                    
                    14.2020-05-12-vim命令
            
                </a>
            

            
        </li>
    

            </ul>
            
        </li>
    
        <li class="chapter " data-level="2.16" >
            
                <span>
            
                    
                    [automate]
            
                </span>
            

            
            <ul class="articles">
                
    
        <li class="chapter " data-level="2.16.1" data-path="../../linux/automate/2020-01-12-redis伪集群创建脚本.html">
            
                <a href="../../linux/automate/2020-01-12-redis伪集群创建脚本.html">
            
                    
                    1.2020-01-12-redis伪集群创建脚本
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="2.16.2" data-path="../../linux/automate/2020-01-12-tomcat集群创建脚本.html">
            
                <a href="../../linux/automate/2020-01-12-tomcat集群创建脚本.html">
            
                    
                    2.2020-01-12-tomcat集群创建脚本
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="2.16.3" data-path="../../linux/automate/2020-01-12-zookeeper自动化脚本.html">
            
                <a href="../../linux/automate/2020-01-12-zookeeper自动化脚本.html">
            
                    
                    3.2020-01-12-zookeeper自动化脚本
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="2.16.4" data-path="../../linux/automate/2020-01-12-其他自动化脚本.html">
            
                <a href="../../linux/automate/2020-01-12-其他自动化脚本.html">
            
                    
                    4.2020-01-12-其他自动化脚本
            
                </a>
            

            
        </li>
    

            </ul>
            
        </li>
    
        <li class="chapter " data-level="2.17" >
            
                <span>
            
                    
                    [MySQL]
            
                </span>
            

            
            <ul class="articles">
                
    
        <li class="chapter " data-level="2.17.1" data-path="../../MySQL/2019-12-31-mysql常用命令.html">
            
                <a href="../../MySQL/2019-12-31-mysql常用命令.html">
            
                    
                    1.2019-12-31-mysql常用命令
            
                </a>
            

            
        </li>
    

            </ul>
            
        </li>
    
        <li class="chapter " data-level="2.18" >
            
                <span>
            
                    
                    [nginx]
            
                </span>
            

            
            <ul class="articles">
                
    
        <li class="chapter " data-level="2.18.1" data-path="../../nginx/2019-12-29-Nginx-Keepalived高可用集群.html">
            
                <a href="../../nginx/2019-12-29-Nginx-Keepalived高可用集群.html">
            
                    
                    1.2019-12-29-Nginx-Keepalived高可用集群
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="2.18.2" data-path="../../nginx/2020-01-16-nginx参数详细说明.html">
            
                <a href="../../nginx/2020-01-16-nginx参数详细说明.html">
            
                    
                    2.2020-01-16-nginx参数详细说明
            
                </a>
            

            
        </li>
    

            </ul>
            
        </li>
    
        <li class="chapter " data-level="2.19" >
            
                <span>
            
                    
                    [other]
            
                </span>
            

            
            <ul class="articles">
                
    
        <li class="chapter " data-level="2.19.1" data-path="../../other/2019-12-28-知识小计.html">
            
                <a href="../../other/2019-12-28-知识小计.html">
            
                    
                    1.2019-12-28-知识小计
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="2.19.2" data-path="../../other/2020-01-04-科学上网.html">
            
                <a href="../../other/2020-01-04-科学上网.html">
            
                    
                    2.2020-01-04-科学上网
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="2.19.3" data-path="../../other/2020-05-13-正则表达式.html">
            
                <a href="../../other/2020-05-13-正则表达式.html">
            
                    
                    3.2020-05-13-正则表达式
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="2.19.4" data-path="../../other/template.html">
            
                <a href="../../other/template.html">
            
                    
                    4.template
            
                </a>
            

            
        </li>
    

            </ul>
            
        </li>
    
        <li class="chapter " data-level="2.20" >
            
                <span>
            
                    
                    [PostgreSQL]
            
                </span>
            

            
            <ul class="articles">
                
    
        <li class="chapter " data-level="2.20.1" data-path="../../PostgreSQL/2019-12-28-PostgreSQL安装文档.html">
            
                <a href="../../PostgreSQL/2019-12-28-PostgreSQL安装文档.html">
            
                    
                    1.2019-12-28-PostgreSQL安装文档
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="2.20.2" data-path="../../PostgreSQL/2019-12-28-Postgres学习笔记.html">
            
                <a href="../../PostgreSQL/2019-12-28-Postgres学习笔记.html">
            
                    
                    2.2019-12-28-Postgres学习笔记
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="2.20.3" data-path="../../PostgreSQL/2019-12-28-脚本MYSQL导出数据到PG.html">
            
                <a href="../../PostgreSQL/2019-12-28-脚本MYSQL导出数据到PG.html">
            
                    
                    3.2019-12-28-脚本MYSQL导出数据到PG
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="2.20.4" data-path="../../PostgreSQL/2020-01-04-docker-PostgreSQL安装文档.html">
            
                <a href="../../PostgreSQL/2020-01-04-docker-PostgreSQL安装文档.html">
            
                    
                    4.2020-01-04-docker-PostgreSQL安装文档
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="2.20.5" data-path="../../PostgreSQL/2020-01-17-阿里云PG主从切换问题.html">
            
                <a href="../../PostgreSQL/2020-01-17-阿里云PG主从切换问题.html">
            
                    
                    5.2020-01-17-阿里云PG主从切换问题
            
                </a>
            

            
        </li>
    

            </ul>
            
        </li>
    
        <li class="chapter " data-level="2.21" >
            
                <span>
            
                    
                    [python]
            
                </span>
            

            
            <ul class="articles">
                
    
        <li class="chapter " data-level="2.21.1" data-path="../../python/2019-12-28-pip-install指定国内源镜像.html">
            
                <a href="../../python/2019-12-28-pip-install指定国内源镜像.html">
            
                    
                    1.2019-12-28-pip-install指定国内源镜像
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="2.21.2" data-path="../../python/2019-12-30-python内置函数.html">
            
                <a href="../../python/2019-12-30-python内置函数.html">
            
                    
                    2.2019-12-30-python内置函数
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="2.21.3" data-path="../../python/2019-12-30-一图搞懂基本python语法 .html">
            
                <a href="../../python/2019-12-30-一图搞懂基本python语法 .html">
            
                    
                    3.2019-12-30-一图搞懂基本python语法 
            
                </a>
            

            
        </li>
    

            </ul>
            
        </li>
    
        <li class="chapter " data-level="2.22" >
            
                <span>
            
                    
                    [redis]
            
                </span>
            

            
            <ul class="articles">
                
    
        <li class="chapter " data-level="2.22.1" data-path="../../redis/2019-12-28-redis5.0.3安装.html">
            
                <a href="../../redis/2019-12-28-redis5.0.3安装.html">
            
                    
                    1.2019-12-28-redis5.0.3安装
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="2.22.2" data-path="../../redis/2019-12-28-redis5.0.3集群搭建.html">
            
                <a href="../../redis/2019-12-28-redis5.0.3集群搭建.html">
            
                    
                    2.2019-12-28-redis5.0.3集群搭建
            
                </a>
            

            
        </li>
    

            </ul>
            
        </li>
    
        <li class="chapter " data-level="2.23" >
            
                <span>
            
                    
                    [tool]
            
                </span>
            

            
            <ul class="articles">
                
    
        <li class="chapter " data-level="2.23.1" data-path="../../tool/2019-12-28-idea高效使用技巧和快捷键.html">
            
                <a href="../../tool/2019-12-28-idea高效使用技巧和快捷键.html">
            
                    
                    1.2019-12-28-idea高效使用技巧和快捷键
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="2.23.2" data-path="../../tool/2019-12-28-PlantUML画图脚本.html">
            
                <a href="../../tool/2019-12-28-PlantUML画图脚本.html">
            
                    
                    2.2019-12-28-PlantUML画图脚本
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="2.23.3" data-path="../../tool/2019-12-30-vscode高效使用.html">
            
                <a href="../../tool/2019-12-30-vscode高效使用.html">
            
                    
                    3.2019-12-30-vscode高效使用
            
                </a>
            

            
        </li>
    

            </ul>
            
        </li>
    
        <li class="chapter " data-level="2.24" >
            
                <span>
            
                    
                    [windows]
            
                </span>
            

            
            <ul class="articles">
                
    
        <li class="chapter " data-level="2.24.1" data-path="../../windows/2020-01-12-本地服务成为互联网服务.html">
            
                <a href="../../windows/2020-01-12-本地服务成为互联网服务.html">
            
                    
                    1.2020-01-12-本地服务成为互联网服务
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="2.24.2" data-path="../../windows/2020-01-12-注册bat为windows服务.html">
            
                <a href="../../windows/2020-01-12-注册bat为windows服务.html">
            
                    
                    2.2020-01-12-注册bat为windows服务
            
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                                <h2 id="&#x7B2C;&#x4E00;&#x90E8;&#x5206;&#xFF1A;&#x5DE5;&#x5177;&#x4ECB;&#x7ECD;&#x90E8;&#x5206;">&#x7B2C;&#x4E00;&#x90E8;&#x5206;&#xFF1A;&#x5DE5;&#x5177;&#x4ECB;&#x7ECD;&#x90E8;&#x5206;</h2>
<p>&#x73B0;&#x5B9E;&#x4F01;&#x4E1A;&#x7EA7;Java&#x5F00;&#x53D1;&#x4E2D;&#xFF0C;&#x6709;&#x65F6;&#x5019;&#x6211;&#x4EEC;&#x4F1A;&#x78B0;&#x5230;&#x4E0B;&#x9762;&#x8FD9;&#x4E9B;&#x95EE;&#x9898;&#xFF1A;</p>
<p>OutOfMemoryError&#xFF0C;&#x5185;&#x5B58;&#x4E0D;&#x8DB3;</p>
<p>&#x5185;&#x5B58;&#x6CC4;&#x9732;</p>
<p>&#x7EBF;&#x7A0B;&#x6B7B;&#x9501;</p>
<p>&#x9501;&#x4E89;&#x7528;&#xFF08;Lock Contention&#xFF09;</p>
<p>Java&#x8FDB;&#x7A0B;&#x6D88;&#x8017;CPU&#x8FC7;&#x9AD8;</p>
<p>......</p>
<p>&#x8FD9;&#x4E9B;&#x95EE;&#x9898;&#x5728;&#x65E5;&#x5E38;&#x5F00;&#x53D1;&#x4E2D;&#x53EF;&#x80FD;&#x88AB;&#x5F88;&#x591A;&#x4EBA;&#x5FFD;&#x89C6;&#xFF08;&#x6BD4;&#x5982;&#x6709;&#x7684;&#x4EBA;&#x9047;&#x5230;&#x4E0A;&#x9762;&#x7684;&#x95EE;&#x9898;&#x53EA;&#x662F;&#x91CD;&#x542F;&#x670D;&#x52A1;&#x5668;&#x6216;&#x8005;&#x8C03;&#x5927;&#x5185;&#x5B58;&#xFF0C;&#x800C;&#x4E0D;&#x4F1A;&#x6DF1;&#x7A76;&#x95EE;&#x9898;&#x6839;&#x6E90;&#xFF09;&#xFF0C;&#x4F46;&#x80FD;&#x591F;&#x7406;&#x89E3;&#x5E76;&#x89E3;&#x51B3;&#x8FD9;&#x4E9B;&#x95EE;&#x9898;&#x662F;Java&#x7A0B;&#x5E8F;&#x5458;&#x8FDB;&#x9636;&#x7684;&#x5FC5;&#x5907;&#x8981;&#x6C42;&#x3002;</p>
<h2 id="jps">jps</h2>
<p>jps&#x4E3B;&#x8981;&#x7528;&#x6765;&#x8F93;&#x51FA;JVM&#x4E2D;&#x8FD0;&#x884C;&#x7684;&#x8FDB;&#x7A0B;&#x72B6;&#x6001;&#x4FE1;&#x606F;&#x3002;</p>
<pre><code class="lang-shell">jps [options] [hostid]
&#x5982;&#x679C;&#x4E0D;&#x6307;&#x5B9A;hostid&#x5C31;&#x9ED8;&#x8BA4;&#x4E3A;&#x5F53;&#x524D;&#x4E3B;&#x673A;&#x6216;&#x670D;&#x52A1;&#x5668;&#x3002;

&#x547D;&#x4EE4;&#x884C;&#x53C2;&#x6570;&#x9009;&#x9879;&#x8BF4;&#x660E;&#x5982;&#x4E0B;&#xFF1A;

-q &#x4E0D;&#x8F93;&#x51FA;&#x7C7B;&#x540D;&#x3001;Jar&#x540D;&#x548C;&#x4F20;&#x5165;main&#x65B9;&#x6CD5;&#x7684;&#x53C2;&#x6570;
-m &#x8F93;&#x51FA;&#x4F20;&#x5165;main&#x65B9;&#x6CD5;&#x7684;&#x53C2;&#x6570;
-l &#x8F93;&#x51FA;main&#x7C7B;&#x6216;Jar&#x7684;&#x5168;&#x9650;&#x540D;
-v &#x8F93;&#x51FA;&#x4F20;&#x5165;JVM&#x7684;&#x53C2;&#x6570;
</code></pre>
<h2 id="jstack">jstack</h2>
<p>jstack&#x4E3B;&#x8981;&#x7528;&#x6765;&#x67E5;&#x770B;&#x67D0;&#x4E2A;Java&#x8FDB;&#x7A0B;&#x5185;&#x7684;&#x7EBF;&#x7A0B;&#x5806;&#x6808;&#x4FE1;&#x606F;&#x3002;&#x8BED;&#x6CD5;&#x683C;&#x5F0F;&#x5982;&#x4E0B;&#xFF1A;</p>
<pre><code class="lang-shell">jstack [option] pid
jstack [option] executable core
jstack [option] [server-id@]remote-hostname-or-ip

&#x547D;&#x4EE4;&#x884C;&#x53C2;&#x6570;&#x9009;&#x9879;&#x8BF4;&#x660E;&#x5982;&#x4E0B;&#xFF1A;
-l long listings&#xFF0C;&#x4F1A;&#x6253;&#x5370;&#x51FA;&#x989D;&#x5916;&#x7684;&#x9501;&#x4FE1;&#x606F;&#xFF0C;&#x5728;&#x53D1;&#x751F;`&#x6B7B;&#x9501;`&#x65F6;&#x53EF;&#x4EE5;&#x7528;jstack -l pid&#x6765;&#x89C2;&#x5BDF;&#x9501;&#x6301;&#x6709;&#x60C5;&#x51B5;
-m mixed mode&#xFF0C;&#x4E0D;&#x4EC5;&#x4F1A;&#x8F93;&#x51FA;Java&#x5806;&#x6808;&#x4FE1;&#x606F;&#xFF0C;&#x8FD8;&#x4F1A;&#x8F93;&#x51FA;C/C++&#x5806;&#x6808;&#x4FE1;&#x606F;&#xFF08;&#x6BD4;&#x5982;Native&#x65B9;&#x6CD5;&#xFF09;
</code></pre>
<p>jstack&#x53EF;&#x4EE5;&#x5B9A;&#x4F4D;&#x5230;&#x7EBF;&#x7A0B;&#x5806;&#x6808;&#xFF0C;&#x6839;&#x636E;&#x5806;&#x6808;&#x4FE1;&#x606F;&#x6211;&#x4EEC;&#x53EF;&#x4EE5;&#x5B9A;&#x4F4D;&#x5230;&#x5177;&#x4F53;&#x4EE3;&#x7801;&#xFF0C;&#x6240;&#x4EE5;&#x5B83;&#x5728;JVM&#x6027;&#x80FD;&#x8C03;&#x4F18;&#x4E2D;&#x4F7F;&#x7528;&#x5F97;&#x975E;&#x5E38;&#x591A;&#x3002;&#x4E0B;&#x9762;&#x6211;&#x4EEC;&#x6765;&#x4E00;&#x4E2A;&#x5B9E;&#x4F8B;&#x627E;&#x51FA;&#x67D0;&#x4E2A;Java&#x8FDB;&#x7A0B;&#x4E2D;&#x6700;&#x8017;&#x8D39;CPU&#x7684;Java&#x7EBF;&#x7A0B;&#x5E76;&#x5B9A;&#x4F4D;&#x5806;&#x6808;&#x4FE1;&#x606F;&#xFF0C;&#x7528;&#x5230;&#x7684;&#x547D;&#x4EE4;&#x6709;ps&#x3001;top&#x3001;printf&#x3001;jstack&#x3001;grep&#x3002;</p>
<p>&#x7B2C;&#x4E00;&#x6B65;&#x5148;&#x627E;&#x51FA;Java&#x8FDB;&#x7A0B;ID&#xFF0C;&#x670D;&#x52A1;&#x5668;&#x4E0A;&#x7684;Java&#x5E94;&#x7528;&#x540D;&#x79F0;&#x4E3A;mrf-center&#xFF1A;</p>
<p>root@ubuntu:/# ps -ef | grep mrf-center | grep -v grep     &#xFF08;&#x6216;&#x8005;&#x76F4;&#x63A5;JPS&#x67E5;&#x770B;&#x8FDB;&#x7A0B;PID&#xFF09;
root     21711     1  1 14:47 pts/3    00:02:10 java -jar mrf-center.jar
&#x7B2C;&#x4E8C;&#x6B65; top -H -p pid
&#x7528;&#x7B2C;&#x4E09;&#x4E2A;&#xFF0C;&#x8F93;&#x51FA;&#x5982;&#x4E0B;&#xFF1A;
   PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND<br> 21936 root      20   0 1747m  21m 9404 S  0.0  0.6   0:00.00 java<br> 21937 root      20   0 1747m  21m 9404 S  0.0  0.6   0:00.14 java<br> 21938 root      20   0 1747m  21m 9404 S  0.0  0.6   0:00.00 java<br> 21939 root      20   0 1747m  21m 9404 S  0.0  0.6   0:00.00 java<br> 21940 root      20   0 1747m  21m 9404 S  0.0  0.6   0:00.00 java                                                                                                                           </p>
<p>TIME&#x5217;&#x5C31;&#x662F;&#x5404;&#x4E2A;Java&#x7EBF;&#x7A0B;&#x8017;&#x8D39;&#x7684;CPU&#x65F6;&#x95F4;&#xFF0C;CPU&#x65F6;&#x95F4;&#x6700;&#x957F;&#x7684;&#x662F;&#x7EBF;&#x7A0B;ID&#x4E3A;21742&#x7684;&#x7EBF;&#x7A0B;&#xFF0C;&#x7528;</p>
<p>printf &quot;%x\n&quot; 21742
&#x5F97;&#x5230;21742&#x7684;&#x5341;&#x516D;&#x8FDB;&#x5236;&#x503C;&#x4E3A;54ee&#xFF0C;&#x4E0B;&#x9762;&#x4F1A;&#x7528;&#x5230;&#x3002;</p>
<p>OK&#xFF0C;&#x4E0B;&#x4E00;&#x6B65;&#x7EC8;&#x4E8E;&#x8F6E;&#x5230;jstack&#x4E0A;&#x573A;&#x4E86;&#xFF0C;&#x5B83;&#x7528;&#x6765;&#x8F93;&#x51FA;&#x8FDB;&#x7A0B;21711&#x7684;&#x5806;&#x6808;&#x4FE1;&#x606F;&#xFF0C;&#x7136;&#x540E;&#x6839;&#x636E;&#x7EBF;&#x7A0B;ID&#x7684;&#x5341;&#x516D;&#x8FDB;&#x5236;&#x503C;grep&#xFF0C;&#x5982;&#x4E0B;&#xFF1A;</p>
<p>root@ubuntu:/# jstack 21711 | grep 54ee
&quot;PollIntervalRetrySchedulerThread&quot; prio=10 tid=0x00007f950043e000 nid=0x54ee in Object.wait()
&#x53EF;&#x4EE5;&#x770B;&#x5230;CPU&#x6D88;&#x8017;&#x5728;PollIntervalRetrySchedulerThread&#x8FD9;&#x4E2A;&#x7C7B;&#x7684;Object.wait()&#xFF0C;&#x6211;&#x627E;&#x4E86;&#x4E0B;&#x6211;&#x7684;&#x4EE3;&#x7801;&#xFF0C;&#x5B9A;&#x4F4D;&#x5230;&#x4E0B;&#x9762;&#x7684;&#x4EE3;&#x7801;&#xFF1A;</p>
<p>// Idle wait
getLog().info(&quot;Thread [&quot; + getName() + &quot;] is idle waiting...&quot;);
schedulerThreadState = PollTaskSchedulerThreadState.IdleWaiting;
long now = System.currentTimeMillis();
long waitTime = now + getIdleWaitTime();
long timeUntilContinue = waitTime - now;
synchronized(sigLock) {
  try {
    if(!halted.get()) {
      sigLock.wait(timeUntilContinue);
    }
  } 
  catch (InterruptedException ignore) {
  }
}
&#x5B83;&#x662F;&#x8F6E;&#x8BE2;&#x4EFB;&#x52A1;&#x7684;&#x7A7A;&#x95F2;&#x7B49;&#x5F85;&#x4EE3;&#x7801;&#xFF0C;&#x4E0A;&#x9762;&#x7684;sigLock.wait(timeUntilContinue)&#x5C31;&#x5BF9;&#x5E94;&#x4E86;&#x524D;&#x9762;&#x7684;Object.wait()&#x3002;</p>
<h2 id="jmap&#xFF08;memory-map&#xFF09;&#x548C;jhat&#xFF08;java-heap-analysis-tool&#xFF09;">jmap&#xFF08;Memory Map&#xFF09;&#x548C;jhat&#xFF08;java Heap Analysis Tool&#xFF09;</h2>
<p>&#x4F7F;&#x7528;jmap &#x547D;&#x4EE4;&#x67E5;&#x770B;&#x5BF9;&#x8C61;&#x5927;&#x5C0F;,dump&#x51FA;hprof&#x6587;&#x4EF6;
jmap&#x7528;&#x6765;&#x67E5;&#x770B;&#x5806;&#x5185;&#x5B58;&#x4F7F;&#x7528;&#x72B6;&#x51B5;&#xFF0C;&#x4E00;&#x822C;&#x7ED3;&#x5408;jhat&#x4F7F;&#x7528;&#x3002;</p>
<p>jmap&#x8BED;&#x6CD5;&#x683C;&#x5F0F;&#x5982;&#x4E0B;&#xFF1A;</p>
<p>jmap [option] pid
jmap [option] executable core
jmap [option] [server-id@]remote-hostname-or-ip
&#x5982;&#x679C;&#x8FD0;&#x884C;&#x5728;64&#x4F4D;JVM&#x4E0A;&#xFF0C;&#x53EF;&#x80FD;&#x9700;&#x8981;&#x6307;&#x5B9A;-J-d64&#x547D;&#x4EE4;&#x9009;&#x9879;&#x53C2;&#x6570;&#x3002;</p>
<p>jmap -permstat pid
&#x6253;&#x5370;&#x8FDB;&#x7A0B;&#x7684;&#x7C7B;&#x52A0;&#x8F7D;&#x5668;&#x548C;&#x7C7B;&#x52A0;&#x8F7D;&#x5668;&#x52A0;&#x8F7D;&#x7684;&#x6301;&#x4E45;&#x4EE3;&#x5BF9;&#x8C61;&#x4FE1;&#x606F;&#xFF0C;&#x8F93;&#x51FA;&#xFF1A;&#x7C7B;&#x52A0;&#x8F7D;&#x5668;&#x540D;&#x79F0;&#x3001;&#x5BF9;&#x8C61;&#x662F;&#x5426;&#x5B58;&#x6D3B;&#xFF08;&#x4E0D;&#x53EF;&#x9760;&#xFF09;&#x3001;&#x5BF9;&#x8C61;&#x5730;&#x5740;&#x3001;&#x7236;&#x7C7B;&#x52A0;&#x8F7D;&#x5668;&#x3001;&#x5DF2;&#x52A0;&#x8F7D;&#x7684;&#x7C7B;&#x5927;&#x5C0F;&#x7B49;&#x4FE1;&#x606F;</p>
<p>&#x4F7F;&#x7528;jmap -histo[:live] pid&#x67E5;&#x770B;&#x5806;&#x5185;&#x5B58;&#x4E2D;&#x7684;&#x5BF9;&#x8C61;&#x6570;&#x76EE;&#x3001;&#x5927;&#x5C0F;&#x7EDF;&#x8BA1;&#x76F4;&#x65B9;&#x56FE;&#xFF0C;&#x5982;&#x679C;&#x5E26;&#x4E0A;live&#x5219;&#x53EA;&#x7EDF;&#x8BA1;&#x6D3B;&#x5BF9;&#x8C61;&#xFF0C;&#x5982;&#x4E0B;&#xFF1A;</p>
<pre><code class="lang-shell">
# jcmd 22589 GC.class_histogram | more  &#x548C; jmap -histo 22589 | more &#x76F8;&#x4F3C;

[kduser@v-jdy-database ~]$ jmap -histo:live 16432 | more

 num     #instances         #bytes  class name
----------------------------------------------
   1:       1025460       94865136  [C
   2:            30       38011744  [Lcom.zaxxer.hikari.util.ConcurrentBag$IConcurrentBagEntry;
   3:       1029948       24718752  java.lang.String
   4:        287284       18301072  [Ljava.lang.Object;
   5:         10392       17870888  [I
...
</code></pre>
<p>&#x8FD8;&#x6709;&#x4E00;&#x4E2A;&#x5F88;&#x5E38;&#x7528;&#x7684;&#x60C5;&#x51B5;&#x662F;&#xFF1A;&#x7528;jmap&#x628A;&#x8FDB;&#x7A0B;&#x5185;&#x5B58;&#x4F7F;&#x7528;&#x60C5;&#x51B5;dump&#x5230;&#x6587;&#x4EF6;&#x4E2D;&#xFF0C;&#x518D;&#x7528;jhat&#x5206;&#x6790;&#x67E5;&#x770B;&#x3002;jmap&#x8FDB;&#x884C;dump&#x547D;&#x4EE4;&#x683C;&#x5F0F;&#x5982;&#x4E0B;&#xFF1A;</p>
<p>jmap -dump:format=b,file=dumpFileName pid
 &#x6211;&#x4E00;&#x6837;&#x5730;&#x5BF9;&#x4E0A;&#x9762;&#x8FDB;&#x7A0B;ID&#x4E3A;21711&#x8FDB;&#x884C;Dump&#xFF1A;
root@ubuntu:/# jmap -dump:format=b,file=/tmp/dump.dat 16432<br>dump&#x51FA;&#x6765;&#x7684;&#x6587;&#x4EF6;&#x53EF;&#x4EE5;&#x7528;MAT&#x3001;VisualVM&#x7B49;&#x5DE5;&#x5177;&#x67E5;&#x770B;&#xFF0C;&#x8FD9;&#x91CC;&#x7528;jhat&#x67E5;&#x770B;&#xFF1A;
&#x6CE8;&#x610F;&#x5982;&#x679C;Dump&#x6587;&#x4EF6;&#x592A;&#x5927;&#xFF0C;&#x53EF;&#x80FD;&#x9700;&#x8981;&#x52A0;&#x4E0A;-J-Xmx512m&#x8FD9;&#x79CD;&#x53C2;&#x6570;&#x6307;&#x5B9A;&#x6700;&#x5927;&#x5806;&#x5185;&#x5B58;&#xFF0C;&#x5373;jhat -J-Xmx512m -port 9998 /tmp/dump.dat&#x3002;&#x7136;&#x540E;&#x5C31;&#x53EF;&#x4EE5;&#x5728;&#x6D4F;&#x89C8;&#x5668;&#x4E2D;&#x8F93;&#x5165;&#x4E3B;&#x673A;&#x5730;&#x5740;:9998&#x67E5;&#x770B;&#x4E86;&#xFF1A;</p>
<p> jhat -port 9998 /tmp/dump.dat</p>
<h2 id="hprof&#xFF08;heapcpu-profiling-tool&#xFF09;">hprof&#xFF08;Heap/CPU Profiling Tool&#xFF09;</h2>
<p>hprof&#x80FD;&#x591F;&#x5C55;&#x73B0;CPU&#x4F7F;&#x7528;&#x7387;&#xFF0C;&#x7EDF;&#x8BA1;&#x5806;&#x5185;&#x5B58;&#x4F7F;&#x7528;&#x60C5;&#x51B5;</p>
<p>&#x8BED;&#x6CD5;&#x683C;&#x5F0F;&#x5982;&#x4E0B;&#xFF1A;</p>
<p>java -agentlib:hprof[=options] ToBeProfiledClass
java -Xrunprof[:options] ToBeProfiledClass
javac -J-agentlib:hprof[=options] ToBeProfiledClass
&#x5B8C;&#x6574;&#x7684;&#x547D;&#x4EE4;&#x9009;&#x9879;&#x5982;&#x4E0B;&#xFF1A;</p>
<p>Option Name and Value  Description                    Default</p>
<hr>
<p>heap=dump|sites|all    heap profiling                 all
cpu=samples|times|old  CPU usage                      off
monitor=y|n            monitor contention             n
format=a|b             text(txt) or binary output     a
file=<file>            write data to file             java.hprof[.txt]
net=<host>:<port>      send data over a socket        off
depth=<size>           stack trace depth              4
interval=<ms>          sample interval in ms          10
cutoff=<value>         output cutoff point            0.0001
lineno=y|n             line number in traces?         y
thread=y|n             thread in traces?              n
doe=y|n                dump on exit?                  y
msa=y|n                Solaris micro state accounting n
force=y|n              force output to <file>         y
verbose=y|n            print messages about dumps     y
&#x6765;&#x51E0;&#x4E2A;&#x5B98;&#x65B9;&#x6307;&#x5357;&#x4E0A;&#x7684;&#x5B9E;&#x4F8B;&#x3002;</file></value></ms></size></port></host></file></p>
<p>CPU Usage Sampling Profiling(cpu=samples)&#x7684;&#x4F8B;&#x5B50;&#xFF1A;</p>
<p>CPU Usage Sampling Profiling(cpu=samples)&#x7684;&#x4F8B;&#x5B50;&#xFF1A;</p>
<p>java -agentlib:hprof=cpu=samples,interval=20,depth=3 Hello</p>
<p>  &#x4E0A;&#x9762;&#x6BCF;&#x9694;20&#x6BEB;&#x79D2;&#x91C7;&#x6837;CPU&#x6D88;&#x8017;&#x4FE1;&#x606F;&#xFF0C;&#x5806;&#x6808;&#x6DF1;&#x5EA6;&#x4E3A;3&#xFF0C;&#x751F;&#x6210;&#x7684;profile&#x6587;&#x4EF6;&#x540D;&#x79F0;&#x662F;java.hprof.txt&#xFF0C;&#x5728;&#x5F53;&#x524D;&#x76EE;&#x5F55;&#x3002; </p>
<p>  CPU Usage Times Profiling(cpu=times)&#x7684;&#x4F8B;&#x5B50;&#xFF0C;&#x5B83;&#x76F8;&#x5BF9;&#x4E8E;CPU Usage Sampling Profile&#x80FD;&#x591F;&#x83B7;&#x5F97;&#x66F4;&#x52A0;&#x7EC6;&#x7C92;&#x5EA6;&#x7684;CPU&#x6D88;&#x8017;&#x4FE1;&#x606F;&#xFF0C;&#x80FD;&#x591F;&#x7EC6;&#x5230;&#x6BCF;&#x4E2A;&#x65B9;&#x6CD5;&#x8C03;&#x7528;&#x7684;&#x5F00;&#x59CB;&#x548C;&#x7ED3;&#x675F;&#xFF0C;&#x5B83;&#x7684;&#x5B9E;&#x73B0;&#x4F7F;&#x7528;&#x4E86;&#x5B57;&#x8282;&#x7801;&#x6CE8;&#x5165;&#x6280;&#x672F;&#xFF08;BCI&#xFF09;&#xFF1A;</p>
<p>javac -J-agentlib:hprof=cpu=times Hello.java</p>
<p>  Heap Allocation Profiling(heap=sites)&#x7684;&#x4F8B;&#x5B50;&#xFF1A;</p>
<p>javac -J-agentlib:hprof=heap=sites Hello.java</p>
<p>  Heap Dump(heap=dump)&#x7684;&#x4F8B;&#x5B50;&#xFF0C;&#x5B83;&#x6BD4;&#x4E0A;&#x9762;&#x7684;Heap Allocation Profiling&#x80FD;&#x751F;&#x6210;&#x66F4;&#x8BE6;&#x7EC6;&#x7684;Heap Dump&#x4FE1;&#x606F;&#xFF1A;</p>
<p>javac -J-agentlib:hprof=heap=dump Hello.java</p>
<p>  &#x867D;&#x7136;&#x5728;JVM&#x542F;&#x52A8;&#x53C2;&#x6570;&#x4E2D;&#x52A0;&#x5165;-Xrunprof:heap=sites&#x53C2;&#x6570;&#x53EF;&#x4EE5;&#x751F;&#x6210;CPU/Heap Profile&#x6587;&#x4EF6;&#xFF0C;&#x4F46;&#x5BF9;JVM&#x6027;&#x80FD;&#x5F71;&#x54CD;&#x975E;&#x5E38;&#x5927;&#xFF0C;&#x4E0D;&#x5EFA;&#x8BAE;&#x5728;&#x7EBF;&#x4E0A;&#x670D;&#x52A1;&#x5668;&#x73AF;&#x5883;&#x4F7F;&#x7528;&#x3002;</p>
<h2 id="jstat&#xFF08;jvm&#x7EDF;&#x8BA1;&#x76D1;&#x6D4B;&#x5DE5;&#x5177;&#xFF09;">jstat&#xFF08;JVM&#x7EDF;&#x8BA1;&#x76D1;&#x6D4B;&#x5DE5;&#x5177;&#xFF09;</h2>
<p>&#x8BED;&#x6CD5;&#x683C;&#x5F0F;&#x5982;&#x4E0B;&#xFF1A;</p>
<p>jstat [ generalOption | outputOptions vmid [interval[s|ms] [count]] ]
vmid&#x662F;Java&#x865A;&#x62DF;&#x673A;ID&#xFF0C;&#x5728;Linux/Unix&#x7CFB;&#x7EDF;&#x4E0A;&#x4E00;&#x822C;&#x5C31;&#x662F;&#x8FDB;&#x7A0B;ID&#x3002;interval&#x662F;&#x91C7;&#x6837;&#x65F6;&#x95F4;&#x95F4;&#x9694;&#x3002;count&#x662F;&#x91C7;&#x6837;&#x6570;&#x76EE;&#x3002;&#x6BD4;&#x5982;&#x4E0B;&#x9762;&#x8F93;&#x51FA;&#x7684;&#x662F;GC&#x4FE1;&#x606F;&#xFF0C;&#x91C7;&#x6837;&#x65F6;&#x95F4;&#x95F4;&#x9694;&#x4E3A;250ms&#xFF0C;&#x91C7;&#x6837;&#x6570;&#x4E3A;4&#xFF1A;</p>
<pre><code class="lang-shell">root@ubuntu:/# jstat -gc 21711 250 4
 S0C    S1C    S0U    S1U      EC       EU        OC         OU       PC     PU    YGC     YGCT    FGC    FGCT     GCT   
192.0  192.0   64.0   0.0    6144.0   1854.9   32000.0     4111.6   55296.0 25472.7    702    0.431   3      0.218    0.649
192.0  192.0   64.0   0.0    6144.0   1972.2   32000.0     4111.6   55296.0 25472.7    702    0.431   3      0.218    0.649
192.0  192.0   64.0   0.0    6144.0   1972.2   32000.0     4111.6   55296.0 25472.7    702    0.431   3      0.218    0.649
192.0  192.0   64.0   0.0    6144.0   2109.7   32000.0     4111.6   55296.0 25472.7    702    0.431   3      0.218    0.649
</code></pre>
<p>&#x8981;&#x660E;&#x767D;&#x4E0A;&#x9762;&#x5404;&#x5217;&#x7684;&#x610F;&#x4E49;&#xFF0C;&#x5148;&#x770B;JVM&#x5806;&#x5185;&#x5B58;&#x5E03;&#x5C40;&#xFF1A;
&#x53EF;&#x4EE5;&#x770B;&#x51FA;&#xFF1A;</p>
<p>&#x5806;&#x5185;&#x5B58; = &#x5E74;&#x8F7B;&#x4EE3; + &#x5E74;&#x8001;&#x4EE3; + &#x6C38;&#x4E45;&#x4EE3;
&#x5E74;&#x8F7B;&#x4EE3; = Eden&#x533A; + &#x4E24;&#x4E2A;Survivor&#x533A;&#xFF08;From&#x548C;To&#xFF09;
&#x73B0;&#x5728;&#x6765;&#x89E3;&#x91CA;&#x5404;&#x5217;&#x542B;&#x4E49;&#xFF1A;</p>
<p>S0C&#x3001;S1C&#x3001;S0U&#x3001;S1U&#xFF1A;Survivor 0/1&#x533A;&#x5BB9;&#x91CF;&#xFF08;Capacity&#xFF09;&#x548C;&#x4F7F;&#x7528;&#x91CF;&#xFF08;Used&#xFF09;
EC&#x3001;EU&#xFF1A;Eden&#x533A;&#x5BB9;&#x91CF;&#x548C;&#x4F7F;&#x7528;&#x91CF;
OC&#x3001;OU&#xFF1A;&#x5E74;&#x8001;&#x4EE3;&#x5BB9;&#x91CF;&#x548C;&#x4F7F;&#x7528;&#x91CF;
PC&#x3001;PU&#xFF1A;&#x6C38;&#x4E45;&#x4EE3;&#x5BB9;&#x91CF;&#x548C;&#x4F7F;&#x7528;&#x91CF;
YGC&#x3001;YGT&#xFF1A;&#x5E74;&#x8F7B;&#x4EE3;GC&#x6B21;&#x6570;&#x548C;GC&#x8017;&#x65F6;
FGC&#x3001;FGCT&#xFF1A;Full GC&#x6B21;&#x6570;&#x548C;Full GC&#x8017;&#x65F6;
GCT&#xFF1A;GC&#x603B;&#x8017;&#x65F6;</p>
<ol>
<li><p>&#x4F7F;&#x7528;jprofiler &#x52A0;&#x8F7D;dump&#x6587;&#x4EF6;</p>
</li>
<li><p>&#x963F;&#x91CC;&#x5DF4;&#x5DF4;&#x5F00;&#x6E90;&#x6027;&#x80FD;&#x8C03;&#x4F18;&#x5229;&#x5668;arthas</p>
</li>
</ol>
<h2 id="&#x5206;&#x6790;&#x5806;&#x5916;&#x5185;&#x5B58;&#x6CC4;&#x9732;">&#x5206;&#x6790;&#x5806;&#x5916;&#x5185;&#x5B58;&#x6CC4;&#x9732;</h2>
<p>JVM NativeMemoryTracking &#x5206;&#x6790;&#x5806;&#x5916;&#x5185;&#x5B58;&#x6CC4;&#x9732;
Native Memory Tracking (NMT) &#x662F;Hotspot VM&#x7528;&#x6765;&#x5206;&#x6790;VM&#x5185;&#x90E8;&#x5185;&#x5B58;&#x4F7F;&#x7528;&#x60C5;&#x51B5;&#x7684;&#x4E00;&#x4E2A;&#x529F;&#x80FD;&#x3002;&#x6211;&#x4EEC;&#x53EF;&#x4EE5;&#x5229;&#x7528;jcmd&#xFF08;jdk&#x81EA;&#x5E26;&#xFF09;&#x8FD9;&#x4E2A;&#x5DE5;&#x5177;&#x6765;&#x8BBF;&#x95EE;NMT&#x7684;&#x6570;&#x636E;&#x3002;</p>
<p>&#x6253;&#x5F00;NMT</p>
<p>NMT&#x5FC5;&#x987B;&#x5148;&#x901A;&#x8FC7;VM&#x542F;&#x52A8;&#x53C2;&#x6570;&#x4E2D;&#x6253;&#x5F00;&#xFF0C;&#x4E0D;&#x8FC7;&#x8981;&#x6CE8;&#x610F;&#x7684;&#x662F;&#xFF0C;&#x6253;&#x5F00;NMT&#x4F1A;&#x5E26;&#x6765;5%-10%&#x7684;&#x6027;&#x80FD;&#x635F;&#x8017;&#x3002;</p>
<pre><code class="lang-shell">-XX:NativeMemoryTracking=[off | summary | detail]
# off: &#x9ED8;&#x8BA4;&#x5173;&#x95ED;
# summary: &#x53EA;&#x7EDF;&#x8BA1;&#x5404;&#x4E2A;&#x5206;&#x7C7B;&#x7684;&#x5185;&#x5B58;&#x4F7F;&#x7528;&#x60C5;&#x51B5;.
# detail: Collect memory usage by individual call sites.
</code></pre>
<p>jcmd&#x67E5;&#x770B;NMT&#x62A5;&#x544A;</p>
<p>&#x901A;&#x8FC7;jcmd&#x67E5;&#x770B;NMT&#x62A5;&#x544A;&#x4EE5;&#x53CA;&#x67E5;&#x770B;&#x5BF9;&#x6BD4;&#x60C5;&#x51B5;&#x3002;</p>
<pre><code class="lang-shell">jcmd &lt;pid&gt; VM.native_memory [summary | detail | baseline | summary.diff | detail.diff | shutdown] [scale= KB | MB | GB]

# summary: &#x5206;&#x7C7B;&#x5185;&#x5B58;&#x4F7F;&#x7528;&#x60C5;&#x51B5;.
# detail: &#x8BE6;&#x7EC6;&#x5185;&#x5B58;&#x4F7F;&#x7528;&#x60C5;&#x51B5;&#xFF0C;&#x9664;&#x4E86;summary&#x4FE1;&#x606F;&#x4E4B;&#x5916;&#x8FD8;&#x5305;&#x542B;&#x4E86;&#x865A;&#x62DF;&#x5185;&#x5B58;&#x4F7F;&#x7528;&#x60C5;&#x51B5;&#x3002;
# baseline: &#x521B;&#x5EFA;&#x5185;&#x5B58;&#x4F7F;&#x7528;&#x5FEB;&#x7167;&#xFF0C;&#x65B9;&#x4FBF;&#x548C;&#x540E;&#x9762;&#x505A;&#x5BF9;&#x6BD4;
# summary.diff: &#x548C;&#x4E0A;&#x4E00;&#x6B21;baseline&#x7684;summary&#x5BF9;&#x6BD4;
# detail.diff: &#x548C;&#x4E0A;&#x4E00;&#x6B21;baseline&#x7684;detail&#x5BF9;&#x6BD4;
# shutdown: &#x5173;&#x95ED;NMT
</code></pre>
<p>VM&#x9000;&#x51FA;&#x65F6;&#x6253;&#x5370;NMT</p>
<p>&#x53EF;&#x4EE5;&#x901A;&#x8FC7;&#x4E0B;&#x9762;VM&#x53C2;&#x6570;&#x5728;JVM&#x9000;&#x51FA;&#x65F6;&#x6253;&#x5370;NMT&#x62A5;&#x544A;&#x3002;</p>
<pre><code class="lang-shell">-XX:+UnlockDiagnosticVMOptions -XX:+PrintNMTStatistics
</code></pre>
<p>NMT&#x5B9E;&#x6218;
&#x75C7;&#x72B6;</p>
<p>&#x67D0;&#x4E2A;&#x670D;&#x52A1;&#xFF08;C&#xFF09;&#x5728;&#x5BA2;&#x6237;&#x73AF;&#x5883;&#x4F7F;&#x7528;&#x540E;&#x53D1;&#x73B0;&#x5176;&#x5185;&#x5B58;&#x5360;&#x7528;&#x4E0D;&#x65AD;&#x53D8;&#x5927;&#x4E14;&#x8FDC;&#x8D85;Xmx&#x6307;&#x5B9A;&#x7684;&#x5927;&#x5C0F;&#xFF0C;&#x5BFC;&#x81F4;&#x6574;&#x4E2A;&#x7CFB;&#x7EDF;&#x56E0;&#x7F3A;&#x5C11;&#x5185;&#x5B58;&#x9020;&#x6210;&#x5176;&#x4ED6;&#x670D;&#x52A1;&#x65E0;&#x6CD5;&#x542F;&#x52A8;&#x3002;&#x5F53;&#x65F6;&#x67E5;&#x770B;&#x5230;&#x5176;RSS&#x5927;&#x7EA6;&#x4E3A;11G&#xFF0C;-Xmx=6G&#x800C;&#x4E14;heap&#x5229;&#x7528;&#x7387;&#x4E0D;&#x5230;50%&#x3002;</p>
<pre><code class="lang-shell">user@hostxxx&gt; prstat -p 2780
PID USERNAME  SIZE   RSS   STATE  PRI   NICE  TIME     CPU   PROCESS/NLWP
2780 user    11G     11G   sleep   59    0    44:16:39 0.0%  java/196

user@hostxxx&gt; /opt/jdk1.8.0_40/bin/jstat -gcutil 2780
S0     S1     E      O      M     CCS    YGC     YGCT       FGC    FGCT     GCT
0.00 100.00  90.60  46.80  98.02  97.10  11323   4049.745   11     225.345   4275.090
</code></pre>
<p>&#x5206;&#x6790;</p>
<p>&#x670D;&#x52A1;&#x901A;&#x8FC7;-Xmx=6G&#x6307;&#x5B9A;&#x6700;&#x5927;&#x5806;&#x5206;&#x914D;&#x4E3A;6G&#xFF0C;&#x4F46;&#x5B9E;&#x9645;RSS&#x5DF2;&#x8FBE;&#x5230;11G&#xFF0C;&#x5F00;&#x59CB;&#x6000;&#x7591;&#x5806;&#x5916;&#x5185;&#x5B58;&#x662F;&#x5426;&#x6709;&#x5185;&#x5B58;&#x6CC4;&#x9732;&#x3002;&#x4E3A;&#x4E86;&#x6709;&#x66F4;&#x597D;&#x8BE6;&#x7EC6;&#x7684;&#x6570;&#x636E;&#xFF0C;&#x5C31;&#x5728;&#x672C;&#x5730;&#x91CD;&#x73B0;&#x8FD9;&#x4E2A;&#x95EE;&#x9898;&#xFF0C;&#x5E76;&#x4E14;&#x6253;&#x5F00;&#x4E86;NMT&#x6301;&#x7EED;&#x76D1;&#x63A7;&#x3002;</p>
<p>NMT&#x7684;Report&#x5982;&#x4E0B;&#xFF0C;&#x91CD;&#x70B9;&#x5173;&#x6CE8;&#x6BCF;&#x4E2A;&#x5206;&#x7C7B;&#x4E0B;&#x7684;commit&#x5927;&#x5C0F;&#xFF0C;&#x8FD9;&#x4E2A;&#x662F;&#x5B9E;&#x9645;&#x4F7F;&#x7528;&#x7684;&#x5185;&#x5B58;&#x5927;&#x5C0F;&#x3002;</p>
<pre><code class="lang-shell">6739: #&#x8FDB;&#x7A0B;ID

Native Memory Tracking:

Total: reserved=8491110KB, committed=7220750KB
-                 Java Heap (reserved=6293504KB, committed=6291456KB) 
                            (mmap: reserved=6293504KB, committed=6291456KB) 

-                     Class (reserved=1107429KB, committed=66189KB) 
                            (classes #11979)
                            (malloc=1509KB #18708) 
                            (mmap: reserved=1105920KB, committed=64680KB) 

-                    Thread (reserved=159383KB, committed=159383KB) 
                            (thread #156)
                            (stack: reserved=158720KB, committed=158720KB)
                            (malloc=482KB #788) 
                            (arena=182KB #310)

-                      Code (reserved=255862KB, committed=41078KB) 
                            (malloc=6262KB #9319) 
                            (mmap: reserved=249600KB, committed=34816KB) 

-                        GC (reserved=449225KB, committed=449225KB) 
                            (malloc=166601KB #1714646) 
                            (mmap: reserved=282624KB, committed=282624KB) 

-                  Compiler (reserved=395KB, committed=395KB) 
                            (malloc=265KB #856) 
                            (arena=131KB #3)

-                  Internal (reserved=146041KB, committed=146041KB) 
                            (malloc=132185KB #276370) 
                            (mmap: reserved=13856KB, committed=13856KB) 

-                    Symbol (reserved=31487KB, committed=31487KB) 
                            (malloc=29209KB #91080) 
                            (arena=2278KB #1)

-    Native Memory Tracking (reserved=33212KB, committed=33212KB) 
                            (malloc=168KB #2575) 
                            (tracking overhead=33044KB)

-               Arena Chunk (reserved=2284KB, committed=2284KB)
                            (malloc=2284KB) 

-                   Unknown (reserved=12288KB, committed=0KB)
                            (mmap: reserved=12288KB, committed=0KB) 

Virtual memory map:
......
</code></pre>
<h2 id="&#x9644;&#x5F55;">&#x9644;&#x5F55;</h2>
<p>&#x53C2;&#x8003;&#xFF1A;
jmap 
<a href="http://josh-persistence.iteye.com/blog/2161848" target="_blank">http://josh-persistence.iteye.com/blog/2161848</a>
NMT
<a href="https://my.oschina.net/foxty/blog/1934968" target="_blank">https://my.oschina.net/foxty/blog/1934968</a></p>

                                
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